The United Nations has warned that the world is facing the largest humanitarian crisis since the conclusion of World War II, when the world body was founded, as widespread starvation and famine are increasingly threatening the lives of over 20 million people in four impoverished countries.

UN Under-Secretary-General for Humanitarian Affairs Stephen O'Brien raised the alarm at the UN Security Council on Friday, adding that "without collective and coordinated global efforts, people will simply starve to death” and "many more will suffer and die from disease.”

He also called for an urgent injection of $4.4 billion by July for Yemen, South Sudan, Somalia and northeastern Nigeria, as well as safe and unimpeded access for humanitarian aid to the four countries "to avert a catastrophe.”

In Yemen, the worst-hit country due to a deadly Saudi military campaign, some 18.8 million people, i.e. over two-thirds of the entire population, are in need of aid, while seven million simply do not know where their next meal will come from.

Back in February, three UN agencies had estimated that 17.1 million people were food insecure in war-torn Yemen.

O'Brien further told the council that there are currently three million more chronically hungry people in the Arab country than in January.

On February 20, the UN International Children's Emergency Fund (UNICEF) warned that 462,000 children were suffering from acute malnutrition in Yemen.